// 页面数据同步管理器 - 全站实时数据同步系统
class PageSyncManager {
    constructor() {
        // 立即初始化基础数据结构，避免异步问题
        this.pageStates = new Map(); // 各页面状态管理
        this.syncQueues = new Map(); // 同步队列
        this.conflictHandlers = new Map(); // 冲突处理器
        this.performanceMonitor = new PerformanceMonitor();
        this.errorHandler = new SyncErrorHandler();
        this.isInitialized = false;
        
        // 等待同步系统初始化完成
        this.waitForSyncSystem().then(() => {
            this.syncSystem = window.syncSystem;
            this.isInitialized = true;
            this.init();
        }).catch(error => {
            console.error('等待同步系统初始化失败:', error);
            // 使用回退机制
            this.initializeWithFallback();
        });
    }

    // 等待同步系统初始化
    async waitForSyncSystem() {
        const maxWaitTime = 10000; // 延长到10秒，避免网络延迟导致过早超时
        const checkInterval = 200; // 调整为200毫秒检查一次，减少检查频率
        
        return new Promise((resolve, reject) => {
            const startTime = Date.now();
            
            const checkSyncSystem = () => {
                if (window.syncSystem && typeof window.syncSystem.subscribe === 'function') {
                    console.log('同步系统已就绪');
                    resolve();
                } else if (Date.now() - startTime > maxWaitTime) {
                    console.warn(`同步系统初始化超时（${maxWaitTime}ms），使用回退机制`);
                    reject(new Error('同步系统初始化超时'));
                } else {
                    setTimeout(checkSyncSystem, checkInterval);
                }
            };
            
            checkSyncSystem();
        });
    }

    // 使用回退机制初始化
    initializeWithFallback() {
        console.warn('使用回退机制初始化页面同步管理器');
        this.syncSystem = {
            // 基本的回退功能
            broadcastMessage: (msg) => console.log('回退广播:', msg),
            getPerformanceMetrics: () => ({ subscriberCount: 0, updateQueueSize: 0, stateSize: 0 }),
            subscribe: (path, callback) => {
                console.log(`回退订阅: ${path}`);
                return () => console.log(`回退取消订阅: ${path}`);
            },
            setData: (path, value, options) => {
                console.log(`回退设置数据: ${path}`, value);
                return Promise.resolve();
            },
            set: (path, value, options) => {
                console.log(`回退设置: ${path}`, value);
                return Promise.resolve();
            }
        };
        this.pageStates = new Map();
        this.syncQueues = new Map();
        this.conflictHandlers = new Map();
        this.performanceMonitor = new PerformanceMonitor();
        this.errorHandler = new SyncErrorHandler();
        
        this.init();
    }

    // 初始化同步管理器
    init() {
        this.setupGlobalListeners();
        this.setupConflictHandlers();
        this.startHealthMonitoring();
        this.setupAutoRecovery();
        
        console.log('页面数据同步管理器已初始化');
    }

    // 设置全局监听器
    setupGlobalListeners() {
        // 监听页面可见性变化
        document.addEventListener('visibilitychange', () => {
            this.handlePageVisibilityChange();
        });

        // 监听网络状态变化
        window.addEventListener('online', () => {
            this.handleNetworkOnline();
        });

        window.addEventListener('offline', () => {
            this.handleNetworkOffline();
        });

        // 监听存储变化
        window.addEventListener('storage', (event) => {
            this.handleStorageChange(event);
        });
    }

    // 设置冲突处理器
    setupConflictHandlers() {
        // 订单数据冲突处理器
        this.conflictHandlers.set('orders', new OrderConflictHandler());
        
        // 产品数据冲突处理器
        this.conflictHandlers.set('products', new ProductConflictHandler());
        
        // 用户数据冲突处理器
        this.conflictHandlers.set('users', new UserConflictHandler());
        
        // 默认冲突处理器
        this.conflictHandlers.set('default', new DefaultConflictHandler());
    }

    // 注册页面同步
    registerPage(pageId, config = {}) {
        // 检查同步系统是否已初始化
        if (!this.isInitialized) {
            console.warn(`页面 ${pageId} 注册时同步系统未初始化，使用回退模式`);
            return this.registerPageWithFallback(pageId, config);
        }

        const pageState = {
            id: pageId,
            config,
            lastSync: Date.now(),
            syncStatus: 'idle',
            pendingUpdates: [],
            listeners: new Set(),
            retryCount: 0
        };

        this.pageStates.set(pageId, pageState);
        this.syncQueues.set(pageId, new SyncQueue(pageId));
        
        // 设置页面特定的数据订阅
        this.setupPageSubscriptions(pageId, config);
        
        console.log(`页面 ${pageId} 已注册同步`);
        
        return pageState;
    }

    // 使用回退模式注册页面
    registerPageWithFallback(pageId, config = {}) {
        const pageState = {
            id: pageId,
            config,
            lastSync: Date.now(),
            syncStatus: 'idle',
            pendingUpdates: [],
            listeners: new Set(),
            retryCount: 0,
            isFallback: true
        };

        this.pageStates.set(pageId, pageState);
        this.syncQueues.set(pageId, new SyncQueue(pageId));
        
        console.log(`页面 ${pageId} 已使用回退模式注册同步`);
        
        return pageState;
    }

    // 设置页面数据订阅
    setupPageSubscriptions(pageId, config) {
        const dataPaths = config.dataPaths || [];
        
        dataPaths.forEach(path => {
            // 检查同步系统是否可用
            if (this.syncSystem && typeof this.syncSystem.subscribe === 'function') {
                const unsubscribe = this.syncSystem.subscribe(path, (value, metadata) => {
                    this.handleDataChange(pageId, path, value, metadata);
                });
                
                const pageState = this.pageStates.get(pageId);
                if (pageState) {
                    pageState.listeners.add(unsubscribe);
                }
            } else {
                console.warn(`同步系统不可用，跳过订阅路径: ${path}`);
            }
        });
    }

    // 处理数据变化
    async handleDataChange(pageId, path, value, metadata) {
        const pageState = this.pageStates.get(pageId);
        if (!pageState) return;

        try {
            this.performanceMonitor.startOperation('data-change');
            
            // 增量同步检查
            if (this.shouldSyncIncrementally(pageState, path, value, metadata)) {
                await this.performIncrementalSync(pageId, path, value, metadata);
            } else {
                await this.performFullSync(pageId, path, value, metadata);
            }
            
            pageState.lastSync = Date.now();
            this.performanceMonitor.endOperation('data-change');
            
        } catch (error) {
            await this.errorHandler.handleSyncError(error, {
                pageId,
                path,
                operation: 'data-change'
            });
        }
    }

    // 检查是否需要增量同步
    shouldSyncIncrementally(pageState, path, value, metadata) {
        // 基于数据大小、变更频率等判断
        const dataSize = JSON.stringify(value).length;
        const timeSinceLastSync = Date.now() - pageState.lastSync;
        
        return dataSize < 1024 && timeSinceLastSync < 5000; // 小数据且近期有同步
    }

    // 执行增量同步
    async performIncrementalSync(pageId, path, value, metadata) {
        const syncQueue = this.syncQueues.get(pageId);
        const incrementalUpdate = {
            type: 'incremental',
            path,
            value,
            metadata,
            timestamp: Date.now()
        };
        
        await syncQueue.add(incrementalUpdate);
        await this.applyIncrementalUpdate(pageId, incrementalUpdate);
    }

    // 执行全量同步
    async performFullSync(pageId, path, value, metadata) {
        const syncQueue = this.syncQueues.get(pageId);
        const fullUpdate = {
            type: 'full',
            path,
            value,
            metadata,
            timestamp: Date.now()
        };
        
        await syncQueue.add(fullUpdate);
        await this.applyFullUpdate(pageId, fullUpdate);
    }

    // 应用增量更新
    async applyIncrementalUpdate(pageId, update) {
        const pageState = this.pageStates.get(pageId);
        const conflictHandler = this.getConflictHandler(update.path);
        
        // 检查冲突
        const conflict = await this.checkConflict(pageId, update);
        if (conflict) {
            const resolved = await conflictHandler.resolve(conflict, update);
            if (!resolved) {
                throw new Error(`增量同步冲突未解决: ${update.path}`);
            }
        }
        
        // 应用更新
        await this.updatePageUI(pageId, update);
        pageState.syncStatus = 'synced';
    }

    // 应用全量更新
    async applyFullUpdate(pageId, update) {
        const pageState = this.pageStates.get(pageId);
        
        // 暂停其他同步操作
        pageState.syncStatus = 'syncing';
        
        try {
            // 重新加载页面数据
            await this.reloadPageData(pageId, update.path, update.value);
            
            pageState.syncStatus = 'synced';
            pageState.retryCount = 0;
            
        } catch (error) {
            pageState.syncStatus = 'error';
            throw error;
        }
    }

    // 检查冲突
    async checkConflict(pageId, update) {
        const pageState = this.pageStates.get(pageId);
        const currentData = this.getCurrentPageData(pageId, update.path);
        
        if (!currentData) return null;
        
        // 时间戳冲突检测（3秒内）
        const timeDiff = update.timestamp - (currentData.timestamp || 0);
        if (timeDiff < 3000) {
            return {
                type: 'timestamp',
                current: currentData,
                incoming: update,
                pageId
            };
        }
        
        return null;
    }

    // 获取冲突处理器
    getConflictHandler(path) {
        const handlerKey = path.split('.')[0]; // 获取数据类型
        return this.conflictHandlers.get(handlerKey) || this.conflictHandlers.get('default');
    }

    // 更新页面UI
    async updatePageUI(pageId, update) {
        // 根据页面类型调用相应的UI更新方法
        switch (pageId) {
            case 'dashboard':
                await this.updateDashboardUI(update);
                break;
            case 'orders':
                await this.updateOrdersUI(update);
                break;
            case 'products':
                await this.updateProductsUI(update);
                break;
            case 'users':
                await this.updateUsersUI(update);
                break;
            default:
                console.warn(`未知页面类型: ${pageId}`);
        }
    }

    // 更新仪表盘UI
    async updateDashboardUI(update) {
        if (window.dashboardManager) {
            if (update.type === 'incremental') {
                await window.dashboardManager.handleIncrementalUpdate(update);
            } else {
                await window.dashboardManager.reloadData();
            }
        }
    }

    // 更新订单页面UI
    async updateOrdersUI(update) {
        if (window.ordersManager) {
            if (update.type === 'incremental') {
                await window.ordersManager.handleOrderUpdate(update);
            } else {
                await window.ordersManager.refreshOrders();
            }
        }
    }

    // 更新产品页面UI
    async updateProductsUI(update) {
        // 检查产品管理器是否存在，如果不存在则跳过
        if (typeof window.productsManager !== 'undefined' && window.productsManager) {
            if (update.type === 'incremental' && window.productsManager.handleProductUpdate) {
                await window.productsManager.handleProductUpdate(update);
            } else if (window.productsManager.loadProducts) {
                await window.productsManager.loadProducts();
            }
        }
    }

    // 更新用户页面UI（已移除用户管理模块）
    async updateUsersUI(update) {
        // 用户管理模块已移除，此功能不再可用
        console.log('用户管理模块已移除，跳过用户UI更新');
    }

    // 重新加载页面数据
    async reloadPageData(pageId, path, value) {
        // 触发页面重新加载数据
        const event = new CustomEvent('pageDataReload', {
            detail: { pageId, path, value }
        });
        
        document.dispatchEvent(event);
    }

    // 获取当前页面数据
    getCurrentPageData(pageId, path) {
        const pageState = this.pageStates.get(pageId);
        if (!pageState) return null;
        
        // 这里需要根据具体页面实现数据获取逻辑
        return null;
    }

    // 处理页面可见性变化
    handlePageVisibilityChange() {
        if (document.hidden) {
            // 页面隐藏，暂停高频率同步
            this.pauseHighFrequencySync();
        } else {
            // 页面显示，恢复同步并检查更新
            this.resumeHighFrequencySync();
            this.checkForUpdates();
        }
    }

    // 处理网络在线
    handleNetworkOnline() {
        console.log('网络恢复，重新开始同步');
        this.resumeAllSync();
        this.retryPendingUpdates();
    }

    // 处理网络离线
    handleNetworkOffline() {
        console.log('网络断开，暂停同步');
        this.pauseAllSync();
    }

    // 处理存储变化
    handleStorageChange(event) {
        if (event.key === this.syncSystem.storageKey) {
            this.triggerGlobalSyncCheck();
        }
    }

    // 暂停高频率同步
    pauseHighFrequencySync() {
        this.pageStates.forEach((pageState) => {
            if (pageState.config.highFrequency) {
                pageState.syncStatus = 'paused';
            }
        });
    }

    // 恢复高频率同步
    resumeHighFrequencySync() {
        this.pageStates.forEach((pageState) => {
            if (pageState.config.highFrequency) {
                pageState.syncStatus = 'idle';
            }
        });
    }

    // 暂停所有同步
    pauseAllSync() {
        this.pageStates.forEach((pageState) => {
            pageState.syncStatus = 'paused';
        });
    }

    // 恢复所有同步
    resumeAllSync() {
        this.pageStates.forEach((pageState) => {
            pageState.syncStatus = 'idle';
        });
    }

    // 重试待处理更新
    async retryPendingUpdates() {
        for (const [pageId, syncQueue] of this.syncQueues) {
            const pending = syncQueue.getPending();
            
            for (const update of pending) {
                try {
                    await this.retryUpdate(pageId, update);
                } catch (error) {
                    console.error(`重试更新失败: ${pageId}`, error);
                }
            }
        }
    }

    // 重试单个更新
    async retryUpdate(pageId, update) {
        const pageState = this.pageStates.get(pageId);
        
        if (pageState.retryCount >= 3) {
            console.warn(`更新重试次数超过限制: ${pageId}`);
            return;
        }
        
        pageState.retryCount++;
        
        try {
            if (update.type === 'incremental') {
                await this.applyIncrementalUpdate(pageId, update);
            } else {
                await this.applyFullUpdate(pageId, update);
            }
            
            pageState.retryCount = 0;
            
        } catch (error) {
            await this.errorHandler.handleRetryError(error, {
                pageId,
                update,
                retryCount: pageState.retryCount
            });
        }
    }

    // 触发全局同步检查
    triggerGlobalSyncCheck() {
        this.pageStates.forEach((pageState) => {
            this.checkForPageUpdates(pageState.id);
        });
    }

    // 检查页面更新
    async checkForPageUpdates(pageId) {
        const pageState = this.pageStates.get(pageId);
        if (!pageState || pageState.syncStatus !== 'idle') return;
        
        try {
            // 检查是否有未同步的数据
            const unsyncedData = await this.getUnsyncedData(pageId);
            
            if (unsyncedData.length > 0) {
                await this.syncUnsyncedData(pageId, unsyncedData);
            }
            
        } catch (error) {
            console.error(`检查页面更新失败: ${pageId}`, error);
        }
    }

    // 检查所有页面更新
    async checkForUpdates() {
        console.log('检查所有页面更新...');
        
        for (const [pageId, pageState] of this.pageStates) {
            if (pageState.syncStatus === 'idle') {
                await this.checkForPageUpdates(pageId);
            }
        }
    }

    // 获取未同步数据
    async getUnsyncedData(pageId) {
        // 实现获取未同步数据的逻辑
        return [];
    }

    // 同步未同步数据
    async syncUnsyncedData(pageId, unsyncedData) {
        const pageState = this.pageStates.get(pageId);
        pageState.syncStatus = 'syncing';
        
        try {
            for (const data of unsyncedData) {
                await this.syncSystem.setData(data.path, data.value, {
                    source: `page-${pageId}`,
                    conflictStrategy: 'merge'
                });
            }
            
            pageState.syncStatus = 'synced';
            
        } catch (error) {
            pageState.syncStatus = 'error';
            throw error;
        }
    }

    // 开始健康监控
    startHealthMonitoring() {
        setInterval(() => {
            this.monitorSyncHealth();
        }, 30000); // 每30秒检查一次
    }

    // 监控同步健康状态
    monitorSyncHealth() {
        const healthReport = {
            timestamp: Date.now(),
            pageCount: this.pageStates.size,
            syncStatus: {},
            performance: this.performanceMonitor.getReport(),
            errors: this.errorHandler.getErrorStats()
        };
        
        this.pageStates.forEach((pageState, pageId) => {
            healthReport.syncStatus[pageId] = {
                status: pageState.syncStatus,
                lastSync: pageState.lastSync,
                retryCount: pageState.retryCount
            };
        });
        
        // 记录健康报告
        this.performanceMonitor.recordHealthReport(healthReport);
        
        // 检查异常状态
        this.checkForAnomalies(healthReport);
    }

    // 检查异常状态
    checkForAnomalies(healthReport) {
        const now = Date.now();
        
        for (const [pageId, status] of Object.entries(healthReport.syncStatus)) {
            // 检查长时间未同步
            if (now - status.lastSync > 300000) { // 5分钟
                console.warn(`页面 ${pageId} 长时间未同步`);
                this.triggerManualSync(pageId);
            }
            
            // 检查重试次数过多
            if (status.retryCount >= 3) {
                console.error(`页面 ${pageId} 重试次数过多`);
                this.triggerErrorRecovery(pageId);
            }
        }
    }

    // 触发手动同步
    triggerManualSync(pageId) {
        const event = new CustomEvent('manualSyncRequired', {
            detail: { pageId }
        });
        
        document.dispatchEvent(event);
    }

    // 触发错误恢复
    triggerErrorRecovery(pageId) {
        const event = new CustomEvent('errorRecoveryRequired', {
            detail: { pageId }
        });
        
        document.dispatchEvent(event);
    }

    // 设置自动恢复
    setupAutoRecovery() {
        // 监听错误恢复事件
        document.addEventListener('errorRecoveryRequired', (event) => {
            this.performAutoRecovery(event.detail.pageId);
        });
    }

    // 执行自动恢复
    async performAutoRecovery(pageId) {
        const pageState = this.pageStates.get(pageId);
        
        try {
            console.log(`开始自动恢复页面: ${pageId}`);
            
            // 重置页面状态
            pageState.syncStatus = 'recovering';
            pageState.retryCount = 0;
            
            // 执行全量同步
            await this.performEmergencySync(pageId);
            
            pageState.syncStatus = 'synced';
            console.log(`页面自动恢复完成: ${pageId}`);
            
        } catch (error) {
            console.error(`页面自动恢复失败: ${pageId}`, error);
            pageState.syncStatus = 'error';
        }
    }

    // 执行紧急同步
    async performEmergencySync(pageId) {
        // 实现紧急同步逻辑
        const syncQueue = this.syncQueues.get(pageId);
        await syncQueue.clear(); // 清空队列
        
        // 触发全量数据重新加载
        await this.reloadPageData(pageId, '*', null);
    }

    // 获取同步状态
    getSyncStatus(pageId = null) {
        if (pageId) {
            return this.pageStates.get(pageId);
        }
        
        return Array.from(this.pageStates.values());
    }

    // 获取性能统计
    getPerformanceStats() {
        return this.performanceMonitor.getReport();
    }

    // 销毁页面同步
    destroyPageSync(pageId) {
        const pageState = this.pageStates.get(pageId);
        if (!pageState) return;
        
        // 取消所有监听器
        pageState.listeners.forEach(unsubscribe => unsubscribe());
        
        // 清理队列
        const syncQueue = this.syncQueues.get(pageId);
        if (syncQueue) {
            syncQueue.destroy();
        }
        
        this.pageStates.delete(pageId);
        this.syncQueues.delete(pageId);
        
        console.log(`页面 ${pageId} 同步已销毁`);
    }
}

// 同步队列类
class SyncQueue {
    constructor(pageId) {
        this.pageId = pageId;
        this.queue = [];
        this.processing = false;
        this.maxSize = 100;
    }

    async add(update) {
        if (this.queue.length >= this.maxSize) {
            // 队列已满，移除最旧的更新
            this.queue.shift();
        }
        
        this.queue.push(update);
        
        if (!this.processing) {
            await this.processQueue();
        }
    }

    async processQueue() {
        this.processing = true;
        
        while (this.queue.length > 0) {
            const update = this.queue.shift();
            
            try {
                await this.processUpdate(update);
            } catch (error) {
                console.error(`处理更新失败: ${this.pageId}`, error);
                // 将失败的更新重新加入队列
                this.queue.unshift(update);
                break;
            }
        }
        
        this.processing = false;
    }

    async processUpdate(update) {
        // 这里会调用页面同步管理器的更新方法
        if (window.pageSyncManager) {
            await window.pageSyncManager.handleDataChange(this.pageId, update.path, update.value, update.metadata);
        }
    }

    getPending() {
        return [...this.queue];
    }

    clear() {
        this.queue = [];
    }

    destroy() {
        this.queue = [];
        this.processing = false;
    }
}

// 性能监控类
class PerformanceMonitor {
    constructor() {
        this.operations = new Map();
        this.healthReports = [];
        this.startTime = Date.now();
    }

    startOperation(operationId) {
        this.operations.set(operationId, {
            start: performance.now(),
            end: null,
            duration: null
        });
    }

    endOperation(operationId) {
        const operation = this.operations.get(operationId);
        if (operation) {
            operation.end = performance.now();
            operation.duration = operation.end - operation.start;
        }
    }

    getReport() {
        const now = Date.now();
        const uptime = now - this.startTime;
        
        return {
            uptime,
            operations: Array.from(this.operations.entries()),
            healthReports: this.healthReports.slice(-10) // 最近10个报告
        };
    }

    recordHealthReport(report) {
        this.healthReports.push(report);
        
        // 保持最多100个报告
        if (this.healthReports.length > 100) {
            this.healthReports.shift();
        }
    }
}

// 错误处理类
class SyncErrorHandler {
    constructor() {
        this.errorStats = {
            total: 0,
            byType: new Map(),
            recent: []
        };
    }

    async handleSyncError(error, context) {
        this.recordError('sync', error, context);
        
        // 根据错误类型采取不同策略
        if (error.name === 'NetworkError') {
            await this.handleNetworkError(error, context);
        } else if (error.name === 'ConflictError') {
            await this.handleConflictError(error, context);
        } else {
            await this.handleGenericError(error, context);
        }
    }

    async handleRetryError(error, context) {
        this.recordError('retry', error, context);
        
        if (context.retryCount >= 3) {
            // 重试次数过多，触发恢复机制
            this.triggerRecovery(context.pageId);
        }
    }

    async handleNetworkError(error, context) {
        console.warn('网络错误，等待重试:', context);
        // 网络错误通常会自动恢复
    }

    async handleConflictError(error, context) {
        console.error('数据冲突错误:', context);
        // 冲突错误需要用户干预或特殊处理
    }

    async handleGenericError(error, context) {
        console.error('通用同步错误:', error, context);
        // 记录错误并继续
    }

    recordError(type, error, context) {
        this.errorStats.total++;
        
        const errorRecord = {
            type,
            error: error.message,
            context,
            timestamp: Date.now(),
            stack: error.stack
        };
        
        // 按类型统计
        if (!this.errorStats.byType.has(type)) {
            this.errorStats.byType.set(type, 0);
        }
        this.errorStats.byType.set(type, this.errorStats.byType.get(type) + 1);
        
        // 记录最近错误
        this.errorStats.recent.push(errorRecord);
        if (this.errorStats.recent.length > 50) {
            this.errorStats.recent.shift();
        }
    }

    triggerRecovery(pageId) {
        const event = new CustomEvent('errorRecoveryRequired', {
            detail: { pageId }
        });
        
        document.dispatchEvent(event);
    }

    getErrorStats() {
        return {
            total: this.errorStats.total,
            byType: Object.fromEntries(this.errorStats.byType),
            recent: this.errorStats.recent.slice(-10)
        };
    }
}

// 冲突处理器基类
class ConflictHandler {
    async resolve(conflict, update) {
        throw new Error('resolve method must be implemented');
    }
}

// 订单冲突处理器
class OrderConflictHandler extends ConflictHandler {
    async resolve(conflict, update) {
        // 订单数据的特殊冲突解决逻辑
        if (conflict.type === 'timestamp') {
            // 对于订单，通常使用最后更新时间
            return update.timestamp > conflict.current.timestamp;
        }
        
        return false;
    }
}

// 产品冲突处理器
class ProductConflictHandler extends ConflictHandler {
    async resolve(conflict, update) {
        // 产品数据的特殊冲突解决逻辑
        if (conflict.type === 'timestamp') {
            // 对于产品信息，合并更改
            return this.mergeProductData(conflict.current, update);
        }
        
        return false;
    }
    
    mergeProductData(current, incoming) {
        // 实现产品数据合并逻辑
        return { ...current, ...incoming };
    }
}

// 用户冲突处理器
class UserConflictHandler extends ConflictHandler {
    async resolve(conflict, update) {
        // 用户数据的特殊冲突解决逻辑
        if (conflict.type === 'timestamp') {
            // 对于用户数据，需要更谨慎的处理
            return this.resolveUserConflict(conflict, update);
        }
        
        return false;
    }
    
    resolveUserConflict(conflict, update) {
        // 实现用户数据冲突解决逻辑
        return update.timestamp > conflict.current.timestamp;
    }
}

// 默认冲突处理器
class DefaultConflictHandler extends ConflictHandler {
    async resolve(conflict, update) {
        // 默认使用最后写入获胜策略
        return update.timestamp > conflict.current.timestamp;
    }
}

// 创建全局页面同步管理器实例
window.pageSyncManager = new PageSyncManager();